How To Find The Answer - Mathematical Problem Solving (1949)

[Music] almost everyday we need to know how to find the answer $10 a month for 12 months would be $120 yeah that can't be right but where'd I make my mistake did I miss something here let's start at the beginning just what do you want to find out well how many months I'll have to pay and what facts will you need to find the answer well these right here total price down payment monthly payments carrying charges maybe I better set these figures on paper so I can work with them total price $63 down payment $12 hey that leaves about 50 dollars to pay let's see balance 51 dollars why even with the 5% charges I shouldn't have to make any more than six $10 payments that's a good estimate Alan now can you figure exactly how many payments well I think so let's see five payments will take care of $50 and the sixth should take care of the other dollar of the balance plus the interest that means interest will be figured for six months five percent of the balance of fifty one dollars there's two fifty five interest for a year then divided by two because it's only six months interest will be 128 my last payment should be to twenty eight then I can't pay for the late in six months yes just as you estimated pretty good if I didn't make another mistake I'll check over these figures and if they're right I'll buy that leg good enough Alan Oh mother that's wonderful and there's a nine and a half yard remnant at that price yes just a minute I'll measure the windows you see nine and a half yard it's a wonderful life that'll be enough let's see five D and one more fix it all together six feet and can you call me back in about ten minutes I just can't figure this out all right goodbye oh nine and a half yards sounds as if you have a problem Bonnie I sure do the baptists remember the material mother's found I can't figure out or there'll be enough to make new drapes or not and that's your problem yes I think I have all the facts I need the drapes to be six feet long we'll need four of them and the material is nine and a half yards long I can't figure any further than that oh don't give up you do have all the information you need but you've forgotten one thing the relation between a foot and a yard so far drapes six feet long 24 feet of material needed oh nine and a half yard and we'll need 24 feet so that's eight yards they'll even be enough to allow for heavens better check it I'll do that right now how do we work out our problem well let's take a look at one more person let's watch for the step by step procedure he uses Oh Harry would you explain just what your problem is sure you see we want to put tile squares on this floor I'm trying to find out how many boxes of tile to order now to know that I need to know that a mentions of this room the size of the tiles and how many come in each box well I have the figures here I measured the room it's 14 feet by 9 feet then I got figures on the tiles from this catalog each box holds 48 tiles and that's enough for 27 square feet of floor the tiles are 9 inches square now that I have all the information I need I want to make an estimate make a guess at the final answer like this the room is 14 by 9 feet Norfolk work well 14 by 10 feet that would mean 140 square feet a box of tiles will cover 27 square feet Oh safe 30 to make figuring easy and there's my estimate about 5 boxes that's just a rough estimate of course I could be wrong by as much as 1 or 2 boxes but you know that your answer won't be as high as say 10 doctors that's right well you have to cut and fit these tiles and there's some waste so we can't figure exactly by square feet I'll have to figure the number of tiles you know sometimes it helps to visualize a problem let's place a few and see how many will need the tiles are 9 inches square that's 3/4 of a foot so for every 3 feet in the length of the floor we'll need 4 tiles 4 tiles in the first three feet four more and four more 12 tiles so we might say that the room is 12 tiles wide now for its length we have 14 feet for tiles for every 3 feet no that won't come out even we better figure it out 14 feet and each tile is 3/4 of a foot how many three-fourths either and 14 or in other words 14 times 4/3 equals what 18 and 2/3 of course I'll need a whole towel for that two-thirds so what I'll need is 19 tiles a long way that will be 228 tiles now since there are 48 tiles in a box we can divide 228 by 48 and the answer is for nearly five so I'll have to buy five boxes of tiles and I'll have a few towels leftover that checks pretty well with my estimate but it's a good thing I figured it out so that's my answer five boxes good enough arrey now let's review the exact steps to use and working off the problem once the problem is formulated first decide what data you need Harry did that first of all second obtain and organize the data Harry obtained data by measuring the room and by checking a catalog third estimate the result get an approximate answer to guide your work fourth perform the needed operations add subtract multiply divide whatever is necessary to obtain an answer from your data and finally check your answer make sure it is correct these are the steps Harry used in a way Alan and vana used them too Alan decided just what facts he needed then he got those facts and organized them so he could better understand how to interpret them he made an estimate of the answer carefully performed the operations and checked his answer Bonnie to decided what data she needed and then obtained the facts by measuring then she did something very important she organized her data and translated the data into units she could compare directly she was then able to estimate the answer perform the operations and check yes this is the procedure we should use in solving any of our mathematical problems [Music]